Study on Preventing Urban Constructed Facilities from Earthquake Disaster

本研究项目的主要目的是寻求建筑结构和已建设施在破坏性地震灾害中的防护方法。本项目包括3个子课题：(1)分层地震动特性研究；(2)建筑物相关结构损伤研究；(3)不规则土体结构对地震反应谱影响的研究。将这些观测和实验结果与预测的理论值进行了比较。从观测和理论结果中发现，断层附近的地面运动的幅度和峰值频率随假定的不连续地质线的相对位置而变化。在振动试验的情况下，发现有地下不规则性的测点的速度响应与计算值相一致，并在SH波入射的情况下研究了地形对地面运动的影响。分析了潜谷地貌的几种类型。采用边界积分方程法对场运动方程进行数值积分。通过对几种地面模型计算的地面运动响应与精确解的比较，验证了该方法的精度。

The main purpose of the research project is to obtain the methods of preventing the building structure and constructed facilities from destructive earthquake disaster. This project comprises 3 sub-project.(1) The study on the characteristics of the earthquake ground motions through layers, (2) the study on the associated structure damage of the building, and (3) the study on the effect o irregular soil structures on response spectra.The characteristics of the earthquake ground motion near the fault are obtained from the simultaneous observation at many points and the motions excited by the vibration generator are measured along the survey line having underground irregular geologic structures. These observational and experimental results are compared with the predicted theoretical values.It is found from observational and theoretical results that the amplitudes and peak frequencies of the ground motion near the fault are variable depending on relative positions to the presumed discontinuous geologic line. In the case of vibration tests, the velocity responses of measure points with underground irregularities are found to be corresponded with the calculated values.The effect of topography on surface motion is investigated in the case of incident SH wave. Several types of buried valley topography are analyzed. The method of boundary integral equation is applied for numerical integration of the field equation of motion. The degree of accuracy of the method is examined by comparing the response of ground motion calculated by this method with that of exact solution for several ground models.